Fast Hybrid Silicon Double-Quantum-Dot Qubit

Proposes a three-electron hybrid qubit in a silicon double quantum dot. The two logical states share $S=1/2$ and $S_z=-1/2$ but differ in the singlet-versus-triplet character of the doubly occupied dot.

Key Results

• Defines the logical singlet/triplet-coupled spin basis for three electrons in two dots.
• Shows how electrical control of singlet-triplet splittings and interdot tunnel coupling can implement fast gates.
• Establishes the double-dot architecture as a compact alternative to a three-dot exchange-only encoding.

Links

• Journal: Physical Review Letters
• arXiv: 1110.6622

Zoo Links

• hybrid-qubit
• spin-qubit
• semiconductor-charge-qubit